This kind of a vehicle air-conditioning unit includes a heating heat exchanger disposed in an air-conditioning case, and a temperature of a blown air blown from the vehicle air-conditioning unit is adjusted by adjusting a ratio of an air flowing to the heating heat exchanger to an air bypassing the heating heat exchanger. For example, it is preferred that the blown air is blown without being heated by the heating heat exchanger during a max cool time (MAX COOL TIME), however, it may be difficult that the air bypasses the heating heat exchanger to flow in the air-conditioning case without any effects of heat of the heating heat exchanger. Therefore, in the vehicle air-conditioning unit, a cool air may be reheated by heat of the heating heat exchanger.
For example, since a cooling heat exchanger and the heating heat exchanger are provided adjacent to each other according to a downsizing of the vehicle air-conditioning unit, a technology for reducing the reheat caused by the heating heat exchanger is important. Various kinds of the technology for reducing the reheat have been proposed conventionally, and a vehicle air-conditioning unit described in Patent Document 1 is one example of that.
The vehicle air-conditioning unit of the Patent Document 1 includes an air-conditioning case, a heating heat exchanger, a rotary door having an axis portion, a door portion and a support portion, and a reheat limiting door connected to the rotary door through a hinge portion. The reheat limiting door is located upstream of the heating heat exchanger and moves between a position for fully opening an airflow passage flowing to the heating heat exchanger and a position for fully closing the airflow passage according to a rotation of the rotary door.
The above-described vehicle air-conditioning unit of Patent Document 1 is capable of reducing the reheat caused by the heating heat exchanger, but a movable mechanism that is the reheat limiting door is necessary for reducing the reheat, and accordingly it makes a structure of the vehicle air-conditioning unit complex.